The Error “App Not Setup: This app is still in development mode, and you don’t have access to it.”, is an error that is invoked when you try to set up an app online and try to integrate the Facebook login. Given below is the snippet of the error you might get:
App Not Setup: This app is still in development mode, and you don't have access to it. Switch to a registered test user or ask an app admin for permissions.
I would like to share with you the steps I took to fix the “App Not Setup: This app is still in development mode, and you don’t have access to it”
Why App Not Setup This app is still in development mode, and you don’t have access to it Error is Seen?
The error, “App Not Setup: This app is still in development mode, and you don’t have access to it” is might be seen because you have not given any email address in the settings of your device. You will also have to change the app review tab to make all the features available to the public.
The detailed solution to fix the error “App Not Setup: This app is still in development mode, and you don’t have access to it”, is given below:
How to fix App Not Setup This app is still in development mode, and you don’t have access to it React Native App Error?
To fix the error, You will have to go your app settings, select basic section and change the contact email section. Also you have to change the app review tab settings as yes for “Do you want to make this app and all its live features available to the general public?” option. Once settings are changed, App Not Setup: This app is still in development mode, and you don’t have access to it React Native App Error will be fixed.
Go to https://developers.facebook.com/apps/ and choose your app.
Navigate to Settings -> Basic -> Include a Contact Email and a URL to your Privacy Policy. The Privacy Policy URL should redirect to website that contains the terms and conditions for your application and data.
To switch from Development to Live, toggle the button at the top of the screen, as seen below.

You have to make sure the configuration is done in a right way.
To fix the error, “App Not Setup: This app is still in development mode, and you don’t have access to it”, you have to follow the below mentioned detailed steps:
Step 1: Change Email Settings
Go to your Settings, then go to the Basic section and inside Contact Email, Give your email address or any email address
Step 2: Change the App Review Tab
Go to your ‘App Review’ Tab, and change the below mentioned setting as “yes“:
Do you want to make this app and all its live features available to the general public?
Once “App Review” Tab settings changed to yes, this should fix the error, “App Not Setup: This app is still in development mode, and you don’t have access to it”
Conclusion
To fix the error “App Not Setup: This app is still in development mode, and you don’t have access to it”, You will have to go your settings and select “basic” tab and change the “contact email” section. Then you will have to change the app review tab as “App Review” Tab settings changed to yes.